SLC19A3 and biotin-responsive basal ganglia disease: We had two patients investigated in our cohort manifesting symptoms of biotin-responsive basal ganglia disease (BBGD), P37, and P38, which presented homozygous mutations c.74dupT (p.Ser26Leufs*19) and c.980-14A>G, respectively, in SLC19A3 [33].